Caption: Pyrococcus furiosus archaea, coloured scanning electron micrograph (SEM). Archaea are single- celled organisms that are similar to bacteria, but also have characteristics of higher organisms, as well as unique characteristics. The thin strands seen here are flagella. Each organism has a group of flagella at one end of the cell that it uses for locomotion. P. furiosus is a hyperthermophile; it is only found living in near-boiling water. At temperatures below 70 degrees Celsius it freezes and dies. It lives in undersea hot vents that are also subject to great pressure and lack oxygen. Instead of oxygen, it uses sulphur for respiration. Magnification: x12,500 when printed 10 centimetres wide.